Plasma enhanced chemical vapor deposition (PECVD) is a well-known process for depositing thin films on a variety of substrates. Several industries varying from glass manufacturing, to semiconductor manufacturing, to plasma display panel manufacturing, rely on PECVD systems to deposit thin films upon substrates. PECVD systems vary widely in their application, just as the films they deposit vary widely in chemistry and quality.
Typical PECVD processes can be controlled by varying process parameters such as gas pressure, power, power pulsing frequency, power duty cycle, pulse shape, and several other parameters. Despite this high degree of customization available in PECVD processes, the industry is continually searching for new ways to improve the PECVD process and to gain more control over the process. In particular, the PECVD industry seeks to utilize PECVD over a wider range of process parameters.
Currently, PECVD can only be used in a limited set of conditions. For other conditions, alternative deposition processes must be used. These alternative deposition processes, such as electron cyclotron resonance (ECR) and sputtering, are not always optimal for many applications. Accordingly, the industry has been searching for ways to extend the application of PECVD into areas traditionally reserved for these alternative deposition methods.
Additionally, PECVD microwave plasma sources have generally been a limited or unsuitable source for ions or other plasma species. Ions sources have many beneficial uses related to PECVD processes. For example, ion sources are often used to pretreat surfaces, such as polymer substrates, in preparation for deposition of thin films. Ion sources are also used to change the chemistry and structure of thin films during plasma deposition processes. Additionally, ion sources can be used to remove charge buildup from films or to clean surfaces. Although alternative ion sources can be combined with microwave plasma sources in PECVD, the PECVD process itself has been insufficient as its own ion source.
Ion sources are available from a variety of vendors and are known in the art. But these ion sources typically suffer from several drawbacks. One drawback is that linear ion sources are overly expensive and complicated for many uses. In fact, many applications that would benefit from ion sources forego their use because of the high costs. Another drawback is that current ion sources tend to produce ions with too much energy. Most ion sources produce ions with over 120 eV of energy. In many applications, ions with this much energy can damage the surface being treated or damage the film being deposited.
Although present devices and methods are functional, they are not sufficiently accurate or otherwise satisfactory. Accordingly, a system and method are needed to address the shortfalls of present technology and to provide other new and innovative features.